Hi, I am trying to understand the isochrounous transfer in usb-uhci.c. Maybe you can help me. The scenario is the following: A cpia camera is supposed to do isochronous image streaming by a given endpoint 1. The cpia driver requests in his open routine 2 isoasap-URBs with ten frame per descriptor and issues periodically the "grabframe" command, which I do actually not know to what urb it resolves.
What I understand: There are 10 tds inserted, for each frame one, recently after the tenth frame the completion interrupt is requested. What misses in the big picture: How does this take place continously.I do not understand the concept of "URB linking". What is the role of the uhci_submit_urb call, the so called resubmit, as the pending urbs of urblist already have linked tds, or not? Weren't there more than 2 iso-urbs with tds, only for 10 frame each one?- but the interupts come from this point on continously. So, who filled in the interrupt causing tds? And why, finally, the image data is delivered only after this "grabframe" command? Hey I know this sounds confusing, but I do not find info for that elsewhere. Thank you Thomas Feldburg ------------------------------------------------------- SF.Net is sponsored by: Speed Start Your Linux Apps Now. Build and deploy apps & Web services for Linux with a free DVD software kit from IBM. Click Now! http://ads.osdn.com/?ad_id=1356&alloc_id=3438&op=click _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
